Tapered leading and side shields for use in a perpendicular magnetic recording head

1. A magnetic head, comprising: a main pole having a trapezoidal cross-section at a media-facing surface thereof, wherein the main pole has a flared shape with a greater width in a cross-track direction at positions away from the media-facing surface than at the media-facing surface; a leading shield positioned near a leading side of the main pole, wherein a leading gap is provided between the main pole and the leading shield; side shields positioned on both sides of the main pole in the cross-track direction adjacent the media-facing surface of the main pole, wherein side gaps are provided between the main pole and both of the side shields; and a trailing gap provided on a trailing side of the main pole at the media-facing surface thereof, wherein a throat height of the side shields at a position closer to the trailing gap is less than the throat height of the side shields at a position closer to the leading gap.

2. The magnetic head as recited in claim 1 , wherein a throat height of the leading shield at the leading gap is less than the throat height of the leading shield at a position up-track from the leading gap.

3. The magnetic head as recited in claim 1 , wherein, at an intersection between the side shields and the leading shield, the throat height of the side shields substantially equals a throat height of the leading shield.

4. The magnetic head as recited in claim 3 , wherein the throat height of the leading shield, at positions up-track from the intersection between the side shields and the leading shield, is greater than the throat height of the leading shield at the intersection between the side shields and the leading shield.

5. The magnetic head as recited in claim 1 , wherein, near an intersection of the leading gap and each of the side gaps, the throat height of the leading shield is less than the throat height of each of the side shields.

6. The magnetic head as recited in claim 1 , wherein the leading shield and the side shields reduce an amount of excess fringe field emanated from a tapered leading edge of the main pole when the magnetic head is operated.

7. The magnetic head as recited in claim 1 , wherein the side gaps comprise alumina, with a proviso that the side gaps do not comprise Ru.

8. The magnetic head as recited in claim 1 , wherein the leading gap comprises alumina, with a proviso that the leading gap does not comprise Ru.

9. A magnetic data storage system, comprising: at least one magnetic head as recited in claim 1 ; a magnetic medium; a drive mechanism for passing the magnetic medium over the at least one magnetic head; and a controller electrically coupled to the at least one magnetic head for controlling operation of the at least one magnetic head.

10. A method for forming a magnetic head as recited in claim 1 , the method comprising: forming a shaping layer above a leading shield; forming a trench in the shaping layer which has tapered side walls; forming a leading gap and side gaps within the trench; forming a main pole above the leading gap and side gaps using the trench, the main pole having a trapezoidal cross-section at a media-facing surface thereof, wherein the main pole has a flared shape with a greater width in a cross-track direction at positions away from the media-facing surface than at the media-facing surface; forming a trailing gap above the main pole; forming side shields disposed adjacent the side gaps on both sides of the main pole in a cross-track direction; and forming a trailing shield disposed above the trailing gap, wherein the side shields are formed such that a throat height at a position closer to the trailing gap is less than a throat height at a position closer to the leading gap.

11. The method as recited in claim 10 , wherein the leading shield is formed such that a throat height at the leading gap is less than a throat height at a position of the leading shield up-track from the leading gap.

12. The method as recited in claim 10 , wherein the side shields and the leading shield are formed such that, at an intersection between the side shields and the leading shield, a throat height of the side shields substantially equals a throat height of the leading shield.

13. The method as recited in claim 12 , wherein the leading shield is formed such that the throat height is greater at positions up-track from the intersection between the side shields and the leading shield than at the intersection between the side shields and the leading shield.

14. The method as recited in claim 10 , wherein the leading shield is formed such that, near an intersection of the leading gap and each of the side gaps, the throat height of the leading shield is less than the throat height of each of the side shields.

15. The method as recited in claim 10 , wherein the leading shield and the side shields reduce an amount of excess fringe field emanated from a tapered leading edge of the main pole when the magnetic head is operated.

16. The method as recited in claim 10 , wherein the side shields and the trailing shield are formed in a single formation process.

17. The method as recited in claim 16 , wherein the single formation process comprises: forming a resist layer in a negative pattern to the trailing shield and the side shields; removing the shaping layer from surfaces of the side gaps which are not in contact with the main pole at a position near the media-facing surface thereof; and depositing a magnetic material adjacent the side gaps and the trailing gap using the pattern of the resist layer to form the trailing shield and the side shields.

18. The method as recited in claim 10 , wherein the side gaps are formed via a Damascene process and comprise alumina, with a proviso that the side gaps do not comprise Ru.

19. The method as recited in claim 10 , wherein the leading gap is formed via a Damascene process and comprises alumina, with a proviso that the leading gap does not comprise Ru.